Q.1
The ball mill can be best used for which kind of feed?
  • a) Wet and Dry
  • b) Coarse and Fine
  • c) Rocks and Bricks
  • d) Any kind of feed
Q.2
What is the ratio of length to diameter of tube mill?
  • a) 4:1
  • b) 3
  • c) Both 3 and 4:1
  • d) 1:2
Q.3
Which of the following forces act on the tumbling mill?
  • a) Tangential force
  • b) Centrifugal force
  • c) Circular force
  • d) Gravitational force
Q.4
Which of the following is true, when operating speed is less than critical speed?
  • a) No grinding
  • b) Effective grinding
  • c) Best grinding
  • d) Bold grinding
Q.5
What is the angle of nip for ball mill?
  • a) 4π2n2 (R-d)/g
  • b) 4π2n2 (R+d)/g
  • c) 4π2n2 (R-r)/g
  • d) 4π2n2 (R-n)/g
Q.6
At critical speed, α = 0 and cos α =what is critical speed?
  • a) n = nc
  • b) 2π = nc
  • c) g = nc
  • d) gn= nc
Q.7
What does the below equation represent?
Questionmechanical-operations-questions-answers7.jpg
  • a) Natural speed
  • b) Full speed
  • c) Optimum speed
  • d) Critical speed
Q.8
What is percentage of tumbling mill speed?
  • a) 80 to 100%
  • b) 65 to 80%
  • c) 50 to 90%
  • d) 10 to 50%
Q.9
Which of the following uses shearing action?
  • a) Buhrstone mill
  • b) Tumbling mill
  • c) Rod mill
  • d) Ball mill
Q.10
What is the feed size for a buhrstone mill?
  • a) Size of peat
  • b) Size of rock
  • c) Size of grain
  • d) Any size
0 h : 0 m : 1 s